Formula 1 is unique in many ways, but perhaps none more so now than the fact all its competitors are also constructors. It is unfortunate for engineering creativity that there is no other professional single-seater, open-cockpit, series that does not use standard chassis, but equally with this distinction present it is imperative that an F1 car remains the ultimate racing machine.
There have been many interpretations of this throughout F1's history, and in the 1970s it came to a head as the 'grandee' constructors held the 'garagistes' in contempt. Enzo Ferrari was the definitive constructor and felt the trend of buying a DFV engine from Cosworth and standard gearbox from Hewland and assembling them to a uniquely designed chassis was diluting the expertise he felt should drive the meritocracy of the competition. Indeed, it even went further than this at the time as there were entrants, some of them moderately successful, who bought complete cars.
By the early 1980s the Formula One Constructors' Association (FOCA) found its place alongside FISA (the forerunner of the current FIA) and it was agreed that the approach of the 'garagistes' was acceptable. Even so it took many years and the advent of the Concorde Agreement - the commercial arrangements between F1 and its various entrants - before the definition of a constructor began to be formalised.